Treating textile materials and articles made therefrom



Patented Oct. 5, 1937 UNITED STATES PATENT OFFICE TREATING TEXTILE MATERIALS ARTICLES MADE THEREFROM No Drawing. Application September 18, 1935, Se-

rial No. 41,175. In Great Britain October 12,

9 Claims. (Cl. 28-1) This invention relates to methods of treating textile materials to improve their appearance .and more particularly to methods of treating lustrous textile. materials such as yarns, and woven, 5 knitted or'other textiles or articles made therefrom in order to reduce their lustre. Although the invention is of primary usefulness in the treatment of yarns and fabrics made from viscose, or other forms of regenerated cellulose 10 artificial silk, or cellulose esters or ethers for instance cellulose acetate artificial silk, in other words rayon in general, it also can be used to advantage for reducing the lustre of natural silk and mercerized materials. 15 For some years after the introduction of synthetic textiles the high lustre of these materials was considered a desirable feature, but a change in taste caused the brilliantly lustrous yarns to lose favour for most purposes, and now there is a decided preference for yarns and fabrics of dull appearance.

This invention therefore, has as an object the provision of methods of improvingthe appearance of textiles in accord with present day taste. A further object is to provide treatments for textiles which will give them'a dull finish highly resistant to removal by laundering. Still another object of this invention is textiles improved in appearance as hereinafter described.

30 Other objects and advantages of the invention will be pointed out in the following description or will be apparent from such description.

These objects are accomplished by my invention wherein various dulling agents are applied 35 to textile materials, or articles made therefrom,

with an acid to desolubilize theco'ating medium. By the definition, -cellulose derivative 'ofthe kind,

incompletely soluble in aqueous caustic alkali so- 5-lution under ordinary conditions, is meant a group of low-substituted cellulose derivatives comprising hydroxyalkylcellulose (glycol ether of cellulose) methyl and ethyl ethers of cellulose and certain inorganic esters of. cellulose, eg the 5o sulfates containing a low percentage of the ester group. To further clarify themeaning of low substituted" as used herein it may be explained that a. low-substituted cellulose derivative is one in which comparatively few of the replaceable" 55 hydroxyl hydrogens of the cellulose mole'c are replaced or substituted by etherifying or esterifying radicals. The adjective low does not refer to the molecular weight of the radicals entering the cellulose molecule as substituents, nor to any of their other characteristics, but merely 5 to the proportion of these radicals introduced.

At the present state of development in the art, applicant is unaware of a better way to describe the particular cellulosic compounds in which he is interested than by the definition low-substituted, (that is, with comparatively few etherii'ying or esterifying radicals introduced), and by pointing out the striking solubility characteristic. This method, it is thought, sharply defines the compounds under consideration to those experienced in the art. It is known that these cellulose bodies when specially prepared under conditions to assure low substitution in the cellulose unit have the property of being substantially insoluble in water or aqueous caustic alkali at ordinary temperatures, but arecapable of being brought into solution in a dilute aqueous solution of a caustic alkali by chilling (in some cases for a predetermined time) below 0 C. until crystals of ice appear, or else by cooling to a lesser stage (+1 to +3 C.) and using acolloid mill or dispersing agents or soluble colloids to aid solution, v as described in my British Patent 410,152. Once dissolved, the temperature of the alkaline solution of cellulose ether or ester can be raised to ordinary or room temperature without causing precipitation or any other bad effect.

In the preferred form of this invention it is desirable that the concentration of caustic alkali should not substantially exceed 5% and the percentage of cellulose derivative dissolved therein should be very low, for example, in the neighborhood of 2 parts per hundred. The proportion of dulling agent to cellulose derivatives may be varied widely. I i 40 As dulling agents, there may be employed numerous suitable materials such as zinc oxide, titanium oxide, stannic oxide, tin phosphate, china clay barium sulphate, antimony oxide and compatible mixtures of these; 'Materials' of this nature may be applied either in suspension as such in the alkaline cellulose derivative solution,,or

certain of them may be applied in solution in the form of alkali soluble compounds, in which latter case the "dulling material is afterward preeipitated by suitable means upon the textile material or article during the operation of fixing the cellulosic medium.

In the operation of the process of this invention the textile material or article made v by weight.

therefrom is passed through a dilute aqueous caustic soda bath containing the dulling agent and cellulose derivative and after thorough wetting it is passed through pressure rolls to remove the excess liquid. Alternatively, the solution may be applied to one side only of the fabric, in which case it may be advisable not to pass the treated fabric through nip rolls if there is danger of forcing the liquid through the fabric.

The fabric is next treated with an agent to neutralize alkalinity and in that way fix the pigmented cellulosic coating on the textile fibres. This may be accomplished by means of a bath of dilute aqueous acid, for example, sulfuric, phosphoric, hydrochloric, formic or acetic acid. Or, if preferable because of the properties of the dulling agent used, there may be substituted an atmosphere of a mildly acid gas such as carbon dioxide. Thus in the case of titanium oxide, stannic oxide, china clay or barium sulphate either a bath of dilute aqueous acid or an atmosphere of carbon dioxide-may be used, whereas in the case of zinc oxide which is more easily soluble in an acid bath, the treatment with carbon dioxide is to be preferred. In this case the zinc oxide will be partly or wholly converted into carbonate.

When the dulling material is applied'in the form of an alkaline solution, the acid chosen for fixing the cellulose derivative must be such as to produce an insoluble precipitate of pigment; for example, when sodium stannate is employed, dilute phosphoric acid may properly be used as precipitating agent.

The acid treated material is passed into a faintly alkaline washing bath and then is washed with water until the wash waters are neutral.

The material is next dried and further finished in known manner.

If desired, the alkaline suspension or solution containing the dissolved cellulose derivatives and the dulling agent may also contain wetting agents such as sulfonic acids: of high molecular weight or softening materials suchas the product sold under the registered trade-mark, "Cirrasol S A.

This invention isillustrated but not limited by the following examples, in which the parts are Example 1 A glycol cellulose ether of the kind incompletely soluble in caustic soda of any concentration but capable of solution on chilling in 5% sodium hydroxide solution until crystals of ice appear is brought into solution :in sodium hydroxide, by mixing 2 parts of the glycol cellulose with- 100 parts of 4.5% sodium hydroxide solution in the presence of 1% calculated on,

weight of glycol cellulose, of the dispersing .agent sold under the registered trade-mark "Perminal" -(an'isopropylated naphthalene sulfonate) according to the method described in British Patent No. 410,152. Bparts of finely ground zinc oxide are then introducedfinto solution, and the whole is stirred. 2 partsof the paste sold under the registered mile-mark. Cirrasol S A? extended with 12 parts of water is then added to the bath. A length of woven viscose'fabric is then passed rapidly through the bath so the period of contact is about .2 seconds -and subsequently passes through the nip rolls to rubber covered rollers and thereafter into a chamber containingan excess of carbondioxid untillthe Example 2 A length of knitted cellulose acetate fabric is passed into a bath made up as in Example 1, containing titanium dioxide instead of 'zinc oxide. After passing through the nip rolls, the fabric is passed rapidly through a bath containing 3% sulphuric acid, after which it is passed through a neutralizing bath of very dilute ammonia, and is then washed with water, and dried.

Where desired, the de-lustred textiles or articles made therefrom can be dyed with suitable dyes, and it willbe understood that when the material is to be dyed it is usually necessary that the dulling'agent should be white.

Lustrous textile materials areeffectively'delustred by the comparatively simple, inexpensive, non-hazardous procedure of thisinvention, and the'dull appearance is remarkably permanent even when the treated materials are submitted to frequent laundering.

As many apparently widelydiflerent embodiments of this invention may be made without departing from the spirit and scope thereof, it

is to be understood that I do not limit myself to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. Lustrous textile materials and articles made therefrom impregnated with a pigmented lowsubstituted cellulose derivative having substantially complete initial solubility in dilute aqueous caustic alkali solution only at temperatures below 10 C. 1

2. Lustrous textile materials and articles made therefrom impregnated 'with a pigmented lowsubstituted cellulose ether having substantially complete initial solubility in dilute aqueous caustic alkali solution only at temperatures below 10 C.

3. Natural and artificial silks and articles made therefrom impregnated with a pigmented lowsubstituted alkyl cellulose having substantially complete initial solubility in dilute aqueous caustic alkali solution only at temperatures below 10 C.

4. Natural and artificial silks and articles made therefrom impregnated with a pigmented lowsubstituted glycol ether of cellulose having substantially complete initial solubility in dilute aqueous caustic alkali solution only at temperatures below 10 C.

5. Natural and artificial silks and articles made therefrom impregnated with a pigmented lowsubstituted inorganic ester of' cellulose having substantially complete initial solubility in dilute aqueous caustic alkali solution only at temperatures below 10 C.

6. Natural and artificial silks and articles made therefrom impregnated with a dulling agent comprising a pigment, a dispersal agent, and a low substituted cellulose ether having substantially complete initial solubility in dilute .aqueous' caustic alkali solution only at temperatures below 10 C. v

"7. A product according to claim 1 in which the pigment is zinc oxide.

8. A product according to claim 1 in which the pigment is titanium dioxide.

9. A product according to .claim the pigment is bariums'ulfate.

1 in which 

